Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove CN2 from the PCB

Measurement:

Measure the resistance across both the live and neutral wires in the spark generator harness.
Expect continuity / zero resistance on each of the wires.
Also visually inspect the condition of the harness.
Are the harness checks satisfactory?